Firearm with a readily interchangeable bolt face

ABSTRACT

A readily replaceable bolt face for a firearm ( 10 ) with a movable slide ( 12 ) that strips a round from a magazine, extracts the spent round from the firing chamber and then ejects the round from the firearm by means of an ejector. A bolt face insert ( 32 ) has an external configuration that is common to a range of calibers, but with a bolt face side ( 66 ) designed to fit the rim of a specific caliber or calibers having the same rim dimension. The insert may be replaced to fit a different caliber without replacing the slide. The bolt face insert is provided with a slot ( 62 ) for the ejector and a groove ( 60 ) to accept an extractor for the specified caliber.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefits of prior filed, co-pending U.S.provisional patent application Ser. No. 60/417,522 filed on Oct. 9,2002.

TECHNICAL FIELD

This invention relates to an improved construction for a firearm,particularly a hand held repeater of semi-automatic or automatic design.More particularly, it relates to an improved construction for a firearmof the type having a longitudinally movable slide on the frame with abolt face that feeds cartridges from a magazine and ejects spentcasings.

BACKGROUND ART

Hand held repeaters are known in the prior art of a semi-automatic orautomatic design, having a bolt or movable slide that strips a roundfrom a magazine. The slide or bolt is driven to the rear from itsbattery position upon firing, extracting the spent round from the firingchamber, which is then ejected from the firearm by means of an ejector.The bolt face or slide face is engineered to encapsulate the base or rimof a specific round, determined by the diameter of the rim for safetyand function purposes.

This invention relates in general to the construction of firearms and,in particular, to the construction of the bolt or slide area called theface. Typically, this face area is manufactured as an integral part ofthe bolt or slide, restricting the use of these major components to aspecific caliber or calibers having the same rim dimension. Othercomponents frequently can be used in the manufacture of firearms of thesame basic type, the difference being the caliber, magazine capacity,sighting arrangements or other features where the same slide or boltcould be used except for their being restricted to a specific caliber bythe bolt or slide face area.

The invention takes into the account the high cost of manufacturing theslide or bolt as a component, the need to decrease inventory cost whereother components are utilized in the production of a variety of firearmsand the inventory of slides needs to be kept high to accommodate thevarying demands, the need of militaries to inventory a variety ofcaliber firearms for special purposes, the cost of replacing firearmswith new ones, should a new caliber be desired as a replacement and thedesire of an end user to be able to change calibers for differentshooting applications.

Accordingly, one object of the present invention is to provide asimplified firearm construction having a readily interchangeable boltface.

Another object of the invention is to provide a simplified constructionfor an interchangeable bolt face insert.

Another object of the invention is to provide an improved firearmconstruction which reduces the cost of the spare parts inventory.

Another object of the invention is to provide an improved firearm, whoseslide or bolt may readily be converted to use a different calibercartridge.

DISCLOSURE OF INVENTION

Briefly stated, the invention uses a slide with the area normallyassociated with the face removed from this component and a recess cutinto the slide for the insertion of an independent part referred to asan interchangeable bolt face insert. The bolt face insert is designed sothat its outside dimension is common to the area removed from the slidefor its insertion. Its inside dimension however, is manufactured toaccommodate a specific cartridge base or rim dimension and cut to acceptan extractor (its retainer) of the proper length, to extract thecartridge that it is designed to encapsulate. By inserting the properinterchangeable bolt face and extractor, the slide now becomes versatileto the use of a wide variety of cartridges. In the case of a firearmutilizing a slide, one need only install a barrel of the desired caliberwith its compatible interchangeable bolt face, the proper extractor anda magazine to shoot a specific caliber. Barrels are required to have thesame outside dimensions, caliber-to-caliber, to mate with their workingsurfaces in the slide. In the case of a firearm not utilizing a slide,but a movable bolt, the same method of insertion and retention areutilized.

The invention is practiced by providing an improved bolt face for afirearm of the type having a frame, a barrel having a bore adapted toreceive a cartridge of a selectable caliber disposed in the frame, aslide or bolt arranged to move longitudinally between a forward and arearward position with respect to the frame and the barrel, the slide orbolt defining a breechblock portion having a longitudinal holetherethrough and a longitudinally spaced ejection chamber, a firing pinlongitudinally slidable in the longitudinal hole to enable it to strikethe cartridge when the slide or bolt is in the forward position, anextractor adapted to match the selected caliber of the cartridge, and anejector fixed to the frame and extending into the ejection chamber whenthe slide is in a rearward position, characterized in that thebreechblock portion defines a semi-circular groove, a bolt face insertcomprising a body having central hole and a semi-circular rim adapted toremovably fit into the semi-circular groove, the insert body having abreechblock side facing the frame breechblock portion and having anoppositely disposed bolt face side facing the extraction chamber whenthe semi-circular rim is inserted into the semi-circular breechblockgroove, the insert bolt face side being adapted to match the selectedcaliber of the cartridge. In its preferred form the bolt face insertdefines an extractor groove adapted to receive the extractor, and theinsert also defines a longitudinal ejector slot adapted to receive theejector.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be better understood by reference to the followingdescription, taken in connection with the accompanying drawings, inwhich:

FIG. 1 is a side elevational drawing, partly in section, of portions ofa semi-automatic firearm, according to the present invention,

FIG. 2 is a top plan view of the firearm of FIG. 1,

FIG. 3 is a side elevational view of the slide of FIG. 2,

FIG. 4 is a bottom plan view of the slide of FIG. 2,

FIG. 5 is a cross-sectional view of the slide, looking in the directionof arrows V-V of FIG. 4,

FIG. 6 is a cross-sectional view of the slide, looking in the directionof arrows VI-VI of FIG. 4,

FIG. 7 is a bottom plan view of a bolt face insert according to thepresent invention,

FIG. 8 is a front elevational view of the bolt face insert,

FIG. 9 is a side elevational view of the bolt face insert,

FIG. 10 is a front elevational view of the bolt face insert similar toFIG. 8,

FIG. 11 is a top view in cross-section taken along lines A-A of FIG. 10,and

FIG. 12 is a front elevational view in cross-section of a slide modifiedto accept the bolt face insert.

BEST MODE OF CARRYING OUT THE INVENTION

Referring now to FIG. 1 of the drawing, the invention is described asembodied in a semi-automatic firearm 10 of the type using aspring-loaded cartridge magazine (not shown) and having a reciprocatingslide 12 adapted to move from a forward position in a rearward directionagainst a recoil spring (not shown) when a cartridge 14 is fired. Duringthe rearward movement, the shell of cartridge 14 is ejected, and duringthe return forward movement, a new cartridge is stripped from themagazine by the extractor and inserted into the bore of a barrel 16 in amanner well known in the art. Slide 12 is reciprocable in tracks upon aframe 18. A hammer 20 is pivotably mounted on frame 18 to strike afiring pin 22, which is longitudinally slidable in the slide 12 so as tostrike the rear of cartridge 14. A trigger 24 is pivotably mounted inthe frame and connected to push or pull a transfer bar 26. Slide 12includes a cam surface 28, which cooperates with a finger 30 to raise orlower the end of transfer bar 26 and release the hammer, when thetransfer bar is pushed or pulled longitudinally by the trigger 24.

The firearm of FIG. 1 is shown with the slide 12 in a forward position,with hammer 20 cocked. A bolt face insert 32 located at the end of asolid breechblock portion of the slide is adjacent and receives the rearof cartridge 14. An extractor (not shown) is engaged over the back endof the cartridge casing ready to cooperate with an ejector (not shown)in a manner well known in the art to remove the casing from the barrelbore and eject the casing through an opening in the slide duringmovement to the rearward position of the slide.

The invention is an improvement in a construction for a semi-automatichand held repeater known in the prior art. It is important to note thatthe bolt face area of a prior art slide is an integral part of the slideand dimensioned for a particular caliber. Converting to a differentcaliber would require a different slide for the firearm.

Referring to FIGS. 2-6 of the drawings, a slide 12 according to thepresent invention is shown. FIG. 2 shows a top view of the slide withsighting ridges 34 and an ejection port 36. Indicated on the rear end ofthe slide are grooved flanges 35, 37, which receive mating flanges onthe frame 12 to hold the slide and guide it in a longitudinal directionon the frame.

FIG. 3 is a side view of the slide indicating ejection port 36, anextractor 38 and a safety pin 40. The separate bolt face insert, to belater described in detail, is indicated by reference number 32.

FIG. 4 is a bottom plan view of the slide 12. The slide includes a solidbreechblock portion 42 and a longitudinally disposed extraction chamber44. A longitudinal hole 46 extends through the solid breechblock portion42 to accommodate a sliding firing pin (not shown).

Referring to FIG. 5 of the drawing, taken along section V-V an extractoris shown at 48 as well as the ejection port 36 and portions 50 of acartridge magazine holding a cartridge 14. Beyond the cartridge 14 thebolt face insert 32 is seen disposed in the slide 12.

Referring to FIG. 6 of the drawing, taken along section VI-VI, bolt faceinsert 32 is shown disposed in the slide 12. The extractor is removedfrom the view to reveal an extractor spring well at 49.

Referring now to FIGS. 7-11, various views of the bolt face insertaccording to the present invention are shown. The bolt face insert,shown generally at 32 has a body 54 with a semi-circular rim 56 and acentral hole 58, both coaxial with an axis 59. Central hole 58 islocated so as to be aligned with the hole 46 in the breechblock portion42 when the bolt face insert is disposed in the slide.

In accordance with one aspect of the present invention, the bolt faceinsert 32 is provided with an extractor groove 60 cut through the rim 56extending perpendicular to axis 59 and adapted to receive an extractor(FIG. 5). The bolt face insert 32 is further provided with alongitudinal ejector slot 62 through the body extending parallel to axis59 and adapted to receive the ejector (not shown). The ejector is fixedto the frame so that it will pass through ejector slot 62 when the slidemoves, and eject the casing through ejection port 36. As indicated inthe cross-section of FIG. 11, the bolt face insert 32 has a breechblockside 64 and a bolt face side 66. The bolt face side 66 is especiallyconfigured to receive the rim of a specific caliber cartridge, forexample by properly dimensioning the bolt face side with the properdiameter 67 as seen in FIG. 10.

Referring to FIG. 12 of the drawing, a cross-section is indicated of thefirearm slide 12. In almost every respect, slide 12 is like a prior artslide, except that it is modified to include a semi-circular groove 70which is cut into the end of the slide 12 adjacent the end of solidbreechblock portion 42 (see FIG. 4). Groove 70 is preferably cut coaxialwith the central hole 46 in the breechblock and is of the properdimension to receive the semi-circular rim 56 of the bolt face insert,so that breechblock hole 46 will line up with insert hole 58.

According to the present invention, the exterior dimensions of thesemi-circular rim of the bolt face insert are always the same, whereasthe bolt face side 66 of the insert 32 is configured according to aselected caliber size. Therefore it is only necessary to substitute onebolt face insert for another, and to substitute a different extractor,magazine and barrel in order to change the caliber of the firearm.

While there has been described what is considered to be the preferredembodiment of the invention, other modifications will occur to thoseskilled in the art. It is desired to secure all such modifications asfall within the true spirit and scope of the invention.

1. An improved bolt face for a firearm of the type having a framedefining a longitudinally extending ejection chamber, a barrel having abore adapted to receive a cartridge of a selected caliber disposed inthe frame, a slide or bolt arranged to move longitudinally between aforward and a rearward position with respect to said frame and saidbarrel, said slide or bolt defining a breechblock portion having alongitudinal hole therethrough, a firing pin longitudinally slidable insaid longitudinal hole to enable it to strike the cartridge when theslide or bolt is in the forward position, an extractor adapted to matchthe selected caliber of the cartridge, and an ejector fixed to the frameand extending into said ejection chamber, characterized in that: saidbreechblock portion defines a semi-circular groove coaxial with saidlongitudinal hole, said firearm having a bolt face insert comprising abody defining a semi-circular rim adapted to removably fit into saidsemi-circular groove, said body having a breechblock side facing theframe breechblock portion and having an oppositely disposed bolt faceside facing the extraction chamber when the insert rim is inserted intothe breechblock groove, and said insert bolt face side adapted to matchthe selected caliber of said cartridge
 2. The combination according toclaim 1, wherein said bolt face insert further defines a longitudinalejector slot located and dimensioned to receive said ejector when saidslide or bolt move to a rearward position.
 3. The combination accordingto claim 1, wherein said bolt face insert further defines an extractorgroove adapted to receive said extractor.
 4. The combination accordingto claim 1, wherein said bolt face insert further defines a central holetherethrough located in the body so as to be aligned with saidlongitudinal hole in said breechblock portion when the insert rim isinserted into the semi-circular groove.
 5. A bolt face insert forproviding a readily changeable bolt face for a bolt or a slide of afirearm, said bolt face insert comprising a body having a longitudinalaxis and defining a semi-circular rim disposed about said axis, saidbody defining a hole therethrough along said axis, said bolt face insertdefining a longitudinal ejector slot through said body extendingparallel to said axis, and said bolt face insert further defining anextractor groove through said semi-circular rim extending perpendicularto said axis.